50 Fun Facts About Tyrannosaurus Rex

What does the 'rex' in Tyrannosaurus rex mean?

'Tyrannos' is Greek for tyrant and 'sauros' for lizard, so the whole name reads 'tyrant lizard the king'.

On which island continent, now part of western North America, did Tyrannosaurus live?

A shallow sea split North America in two at the time; T. rex had a wider range than any other tyrannosaurid.

Tyrannosaurus lived roughly how many million years ago?

That puts it in the very last age of the Cretaceous, among the final non-avian dinosaurs before the asteroid.

How many clawed fingers did Tyrannosaurus have on each hand?

A splint-like third metacarpal survived as a remnant; the 1915 museum mount wrongly gave it three-fingered Allosaurus arms.

According to most modern estimates, Tyrannosaurus could exceed what mass?

That is with a length past 13 metres and hips 3.7 to 4 metres off the ground.

Which Asian dinosaur is so close to Tyrannosaurus that some treat it as a species of the same genus?

Named Tyrannosaurus bataar by Evgeny Maleev in 1955, it was moved to its own genus a decade later.

The first partial skeleton of T. rex was found in eastern Wyoming in 1900 by whom?

'Mr Bones' found a second one in Montana two years later; for decades those were the only specimens known.

Who named Tyrannosaurus rex in 1905?

He named a second skeleton under a different name in the same paper, realised in 1906 they were the same species, and kept Tyrannosaurus.

What was the discarded 1905 name for the specimen later recognised as T. rex?

That material now sits in London's Natural History Museum; a 2018 tyrannosaurid, Dynamoterror, was named in its honour.

For how much was the T. rex type specimen sold to Pittsburgh's Carnegie Museum in 1941?

About $150,000 in today's money, and a bargain next to the $31.8 million Stan fetched in 2020.

Sue, the most complete T. rex, was discovered in 1990 by whom?

She was exploring cliffs on the Cheyenne River reservation while colleagues fixed a flat tyre; the skeleton took her name.

Sue was auctioned in 1997 for how much?

It was then the highest price ever paid for a fossil; the Field Museum's staff spent over 25,000 hours freeing the bones from rock.

Sue is on permanent display in which city?

The Field Museum's mount was built in New Jersey, shipped back and unveiled on 17 May 2000.

Bone studies suggested Sue reached full size at what age?

She was first thought to have died at 28, the oldest tyrannosaur known at the time; newer estimates say 27 to 33.

Stan, the T. rex sold for $31.8 million in 2020, was auctioned by which house?

It went as part of a 20th Century Evening Sale in New York and now stands in the Natural History Museum Abu Dhabi.

Stan's skeleton has a healed hole in the back of the skull about the size of what?

He is the second most complete T. rex, with 199 bones, and named for amateur palaeontologist Stan Sacrison.

Bucky, found by 20-year-old Bucky Derflinger in 1998, was the first T. rex to preserve which bone?

He is displayed at the Children's Museum of Indianapolis, and his finder remains the youngest person to discover a T. rex.

Scotty, possibly the largest T. rex known, is housed at a museum in which Canadian province?

The estimate came from the circumference of the femur; Sue's maximum mass estimates run 8.4 to 9.2 t.

Trix, on show in Leiden, is named after which former monarch?

She is thought to be the oldest T. rex known and one of only two on permanent display in mainland Europe.

The largest T. rex skull found measures about how long?

It was extremely wide at the back but narrow at the snout, giving unusually good binocular vision.

The largest T. rex tooth found is estimated at how long including the root?

The teeth have been likened to 'lethal bananas' rather than daggers, thick and ridged to survive biting and pulling.

Unlike most carnivorous dinosaurs, the tip of T. rex's upper jaw was what shape?

That let it rip out more tissue and bone per bite, at the cost of extra stress on the front teeth.

How many neck vertebrae did Tyrannosaurus have?

The neck was short, deep and S-curved to hold up the massive head; the tail probably had at least forty vertebrae.

A 2012 study estimated an adult T. rex could bite with up to what force in its back teeth?

That is roughly 12,800 pounds-force, the most powerful bite of any land animal that has ever lived.

A T. rex arm measured only about how long?

Osborn guessed in 1906 they gripped a mate; others have suggested slashing prey, or simply shrinking to stay out of the way of the jaws.

Which palaeontologist championed the idea that T. rex was purely a scavenger, not a predator?

He argued the arms were too short to grip prey; healed bite wounds on hadrosaurs and horned dinosaurs suggest T. rex did attack live animals.

Healed T. rex tooth marks on the brow horn and frill of which dinosaur suggest it survived an attack?

The bitten horn was broken and had regrown, so the herbivore evidently won that encounter.

Tooth marks on the foot bones and humerus of one T. rex specimen are evidence of what behaviour?

At the very least T. rex scavenged its own kind; other tyrannosaurids may have done the same.

Smooth-edged holes in T. rex skulls may come from a parasite similar to which bird disease?

The infection would have eroded the jaw, and in a severe case could have starved the animal.

Most estimates put T. rex's top running speed at roughly what?

A 2017 model suggested anything above 18 km/h would have shattered its leg bones, and its preferred walking pace was under 5 km/h.

A study found T. rex had a binocular field of about 55 degrees, wider than which modern bird's?

The narrow snout and wide rear skull are what made such depth perception possible.

T. rex's sense of smell has been compared to which modern scavenging bird?

Its olfactory bulbs and nerves were huge relative to brain size, and it had the biggest brain of any large non-avian dinosaur.

The specimen B-rex was shown to be female because its femur contained what?

Medullary tissue forms only in ovulating female birds; its presence in a theropod is more evidence of the bird-dinosaur link.

In 2005 Mary Higby Schweitzer announced the recovery of what from a T. rex leg bone?

The bone had been broken for shipping and deliberately left untreated so she could test it; sceptics later argued the material was biofilm.

Which large feathered tyrannosauroid cast doubt on big tyrannosaurs having lost their feathers?

Skin impressions still suggest adult T. rex was mostly scaly, with any feathering confined to the top of the trunk.

The upright, tail-dragging T. rex mount unveiled by Osborn in 1915 stood uncorrected for how many years?

It inspired countless paintings and films; Jurassic Park finally showed the public the horizontal, tail-balanced posture.

The juvenile skeleton 'Jane', described in 2001, was later made the holotype of which disputed genus?

Whether Nanotyrannus is a real dwarf tyrant or just a young T. rex is one of the field's longest-running arguments.

Which fossil formation, spanning Montana and the Dakotas, has produced Sue, Stan, Bucky and Jane?

T. rex is the only large theropod known from it, so any big track there is presumed to be a tyrannosaur's.

Bone fragments attributed to tyrannosaurs have been found in coprolites, meaning what?

Even so, T. rex teeth were not built to methodically crack bones for marrow the way hyenas do.

A hatchling T. rex is estimated to have weighed at least how much?

That implies a mother might have laid something like 21 to 32 eggs at a time.

Which palaeontologist suggested T. rex hunted in packs, citing a South Dakota site with three skeletons together?

He compared it to Tarbosaurus and Albertosaurus finds; group hunting would have helped against horned and armoured prey.

Which 2024-described species has been proposed as a second, older Tyrannosaurus?

Its describers still concluded the genus arose in western North America, with ancestors that possibly migrated from Asia.

Science writer Riley Black has called Tyrannosaurus what?

It has been one of the best-known dinosaurs since the early 20th century and a museum crowd-puller ever since.

In Jurassic Park, the T. rex escapes because what has been switched off?

Screenwriter David Koepp kept it offscreen until the breakout, borrowing the trick from Jaws.

Which character does the T. rex devour in Jurassic Park?

The lawyer is eaten off a toilet; Malcolm is only injured, and the T. rex later saves the survivors from the raptors.

The palaeontologist who found the first T. rex skeletons was known by what nickname?

He worked for the American Museum of Natural History, whose 1915 T. rex mount became the world's most influential dinosaur skeleton.

A tooth found in July 1874 near Golden, Colorado, is now documented as the earliest what?

Student Peter Dotson picked it up on South Table Mountain, decades before anyone knew what T. rex was.

A 2021 study estimated the adult Tyrannosaurus population alive at any one time at roughly how many?

Charles Marshall's team reckoned an area the size of Washington D.C. could support only two adults, while California-sized territory could hold 3,800.

Collagen proteins recovered from T. rex bone in 2007 most closely matched those of which living animal?

Frogs and newts were the next closest matches, supporting the bird-dinosaur link from biochemistry rather than bones.

T. rex's unusually long cochlea suggests it heard best in which range of sound?

The length of the cochlea is linked to how important hearing was to an animal's behaviour.